Abstract. The Metafor project has developed a common information model (CIM) using the
ISO19100 series formalism to describe numerical experiments
carried out by the Earth system modelling community, the models they use, and
the simulations that result. Here we describe the mechanism by which the CIM
was developed, and its key properties. We introduce the conceptual and
application versions and the controlled vocabularies developed in the context
of supporting the fifth Coupled Model Intercomparison Project (CMIP5). We
describe how the CIM has been used in experiments to describe model coupling
properties and describe the near term expected evolution of the CIM.